Teach the blkid library about ext4/ext4dev

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/lib/blkid/probe.c b/lib/blkid/probe.c
index 32d9f3f..f7bb491 100644 (file)
--- a/lib/blkid/probe.c
+++ b/lib/blkid/probe.c
@@ -131,7 +131,8 @@ static void set_uuid(blkid_dev dev, uuid_t uuid, char *tag)
        }
 }
 
-static void get_ext2_info(blkid_dev dev, unsigned char *buf)
+static void get_ext2_info(blkid_dev dev, struct blkid_magic *id,
+                         unsigned char *buf)
 {
        struct ext2_super_block *es = (struct ext2_super_block *) buf;
        const char *label = 0;
@@ -146,61 +147,123 @@ static void get_ext2_info(blkid_dev dev, unsigned char *buf)
        blkid_set_tag(dev, "LABEL", label, sizeof(es->s_volume_name));
 
        set_uuid(dev, es->s_uuid, 0);
+
+       if ((es->s_feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL) &&
+           !uuid_is_null(es->s_journal_uuid))
+               set_uuid(dev, es->s_journal_uuid, "EXT_JOURNAL");
+
+       if (strcmp(id->bim_type, "ext2") &&
+           ((blkid_le32(es->s_feature_incompat) &
+             EXT2_FEATURE_INCOMPAT_UNSUPPORTED) == 0))
+               blkid_set_tag(dev, "SEC_TYPE", "ext2", sizeof("ext2"));
 }
 
-static int probe_ext3(struct blkid_probe *probe, 
-                     struct blkid_magic *id __BLKID_ATTR((unused)), 
+static int probe_ext4dev(struct blkid_probe *probe,
+                        struct blkid_magic *id,
+                        unsigned char *buf)
+{
+       struct ext2_super_block *es;
+       es = (struct ext2_super_block *)buf;
+
+       /* Distinguish between ext4dev and other filesystems */
+       if ((blkid_le32(es->s_flags) & EXT2_FLAGS_TEST_FILESYS) == 0)
+               return -BLKID_ERR_PARAM;
+
+       /* Distinguish from jbd */
+       if (blkid_le32(es->s_feature_incompat) &
+           EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
+               return -BLKID_ERR_PARAM;
+
+       /* ext4dev requires a journal */
+       if (!(blkid_le32(es->s_feature_compat) &
+             EXT3_FEATURE_COMPAT_HAS_JOURNAL))
+               return -BLKID_ERR_PARAM;
+
+       get_ext2_info(probe->dev, id, buf);
+       return 0;
+}
+
+static int probe_ext4(struct blkid_probe *probe, struct blkid_magic *id,
                      unsigned char *buf)
 {
        struct ext2_super_block *es;
        es = (struct ext2_super_block *)buf;
 
-       /* Distinguish between jbd and ext2/3 fs */
+       /* Distinguish from ext4dev */
+       if (blkid_le32(es->s_flags) & EXT2_FLAGS_TEST_FILESYS)
+               return -BLKID_ERR_PARAM;
+
+       /* Distinguish from jbd */
        if (blkid_le32(es->s_feature_incompat) & 
            EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
                return -BLKID_ERR_PARAM;
 
-       /* Distinguish between ext3 and ext2 */
+       /* ext4 requires journal */
        if (!(blkid_le32(es->s_feature_compat) &
              EXT3_FEATURE_COMPAT_HAS_JOURNAL))
                return -BLKID_ERR_PARAM;
 
-       get_ext2_info(probe->dev, buf);
+       /* Ext4 has at least one feature which ext3 doesn't understand */
+       if (!(blkid_le32(es->s_feature_ro_compat) &
+             EXT3_FEATURE_RO_COMPAT_UNSUPPORTED) &&
+           !(blkid_le32(es->s_feature_incompat) &
+             EXT3_FEATURE_INCOMPAT_UNSUPPORTED))
+               return -BLKID_ERR_PARAM;
 
-       if ((es->s_feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL) &&
-           !uuid_is_null(es->s_journal_uuid))
-               set_uuid(probe->dev, es->s_journal_uuid, "EXT_JOURNAL");
+       get_ext2_info(probe->dev, id, buf);
+       return 0;
+}
+
+static int probe_ext3(struct blkid_probe *probe, struct blkid_magic *id,
+                     unsigned char *buf)
+{
+       struct ext2_super_block *es;
+       es = (struct ext2_super_block *)buf;
+
+       /* Distinguish from ext4dev */
+       if (blkid_le32(es->s_flags) & EXT2_FLAGS_TEST_FILESYS)
+               return -BLKID_ERR_PARAM;
 
-       blkid_set_tag(probe->dev, "SEC_TYPE", "ext2", sizeof("ext2"));
+       /* ext3 requires journal */
+       if (!(blkid_le32(es->s_feature_compat) &
+             EXT3_FEATURE_COMPAT_HAS_JOURNAL))
+               return -BLKID_ERR_PARAM;
 
+       /* Any features which ext3 doesn't understand */
+       if ((blkid_le32(es->s_feature_ro_compat) &
+            EXT3_FEATURE_RO_COMPAT_UNSUPPORTED) ||
+           (blkid_le32(es->s_feature_incompat) &
+            EXT3_FEATURE_INCOMPAT_UNSUPPORTED))
+               return -BLKID_ERR_PARAM;
+
+       get_ext2_info(probe->dev, id, buf);
        return 0;
 }
 
-static int probe_ext2(struct blkid_probe *probe,
-                     struct blkid_magic *id __BLKID_ATTR((unused)), 
+static int probe_ext2(struct blkid_probe *probe, struct blkid_magic *id,
                      unsigned char *buf)
 {
        struct ext2_super_block *es;
 
        es = (struct ext2_super_block *)buf;
 
-       /* Distinguish between jbd and ext2/3 fs */
-       if (blkid_le32(es->s_feature_incompat) & 
-           EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
-               return -BLKID_ERR_PARAM;
-       
        /* Distinguish between ext3 and ext2 */
        if ((blkid_le32(es->s_feature_compat) &
              EXT3_FEATURE_COMPAT_HAS_JOURNAL))
                return -BLKID_ERR_PARAM;
 
-       get_ext2_info(probe->dev, buf);
+       /* Any features which ext2 doesn't understand */
+       if ((blkid_le32(es->s_feature_ro_compat) &
+            EXT2_FEATURE_RO_COMPAT_UNSUPPORTED) ||
+           (blkid_le32(es->s_feature_incompat) &
+            EXT2_FEATURE_INCOMPAT_UNSUPPORTED))
+               return -BLKID_ERR_PARAM;
 
+       get_ext2_info(probe->dev, id, buf);
        return 0;
 }
 
-static int probe_jbd(struct blkid_probe *probe,
-                    struct blkid_magic *id __BLKID_ATTR((unused)), 
+static int probe_jbd(struct blkid_probe *probe, struct blkid_magic *id,
                     unsigned char *buf)
 {
        struct ext2_super_block *es = (struct ext2_super_block *) buf;
@@ -209,7 +272,7 @@ static int probe_jbd(struct blkid_probe *probe,
              EXT3_FEATURE_INCOMPAT_JOURNAL_DEV))
                return -BLKID_ERR_PARAM;
 
-       get_ext2_info(probe->dev, buf);
+       get_ext2_info(probe->dev, id, buf);
 
        return 0;
 }
@@ -833,6 +896,8 @@ static struct blkid_magic type_array[] = {
   { "oracleasm", 0,    32,  8, "ORCLDISK",             probe_oracleasm },
   { "ntfs",     0,      3,  8, "NTFS    ",             probe_ntfs },
   { "jbd",      1,   0x38,  2, "\123\357",             probe_jbd },
+  { "ext4dev",  1,   0x38,  2, "\123\357",             probe_ext4dev },
+  { "ext4",     1,   0x38,  2, "\123\357",             probe_ext4 },
   { "ext3",     1,   0x38,  2, "\123\357",             probe_ext3 },
   { "ext2",     1,   0x38,  2, "\123\357",             probe_ext2 },
   { "reiserfs",         8,   0x34,  8, "ReIsErFs",             probe_reiserfs },

diff --git a/lib/blkid/probe.h b/lib/blkid/probe.h
index f22fb2e..2cbd617 100644 (file)
--- a/lib/blkid/probe.h
+++ b/lib/blkid/probe.h
@@ -82,11 +82,61 @@ struct ext2_super_block {
        __u32   s_first_meta_bg;
        __u32   s_mkfs_time;
        __u32   s_jnl_blocks[17];
-       __u32   s_reserved[172];
+       __u32   s_blocks_count_hi;
+       __u32   s_r_blocks_count_hi;
+       __u32   s_free_blocks_hi;
+       __u16   s_min_extra_isize;
+       __u16   s_want_extra_isize;
+       __u32   s_flags;
+       __u16   s_raid_stride;
+       __u16   s_mmp_interval;
+       __u64   s_mmp_block;
+       __u32   s_raid_stripe_width;
+       __u32   s_reserved[163];
 };
-#define EXT3_FEATURE_COMPAT_HAS_JOURNAL                0x00000004
-#define EXT3_FEATURE_INCOMPAT_RECOVER          0x00000004
-#define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV      0x00000008
+
+/* for s_flags */
+#define EXT2_FLAGS_TEST_FILESYS                0x0004
+
+/* for s_feature_compat */
+#define EXT3_FEATURE_COMPAT_HAS_JOURNAL                0x0004
+
+/* for s_feature_ro_compat */
+#define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER    0x0001
+#define EXT2_FEATURE_RO_COMPAT_LARGE_FILE      0x0002
+#define EXT2_FEATURE_RO_COMPAT_BTREE_DIR       0x0004
+#define EXT4_FEATURE_RO_COMPAT_HUGE_FILE       0x0008
+#define EXT4_FEATURE_RO_COMPAT_GDT_CSUM                0x0010
+#define EXT4_FEATURE_RO_COMPAT_DIR_NLINK       0x0020
+#define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE     0x0040
+
+/* for s_feature_incompat */
+#define EXT2_FEATURE_INCOMPAT_FILETYPE         0x0002
+#define EXT3_FEATURE_INCOMPAT_RECOVER          0x0004
+#define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV      0x0008
+#define EXT2_FEATURE_INCOMPAT_META_BG          0x0010
+#define EXT4_FEATURE_INCOMPAT_EXTENTS          0x0040 /* extents support */
+#define EXT4_FEATURE_INCOMPAT_64BIT            0x0080
+#define EXT4_FEATURE_INCOMPAT_MMP              0x0100
+#define EXT4_FEATURE_INCOMPAT_FLEX_BG          0x0200
+
+#define EXT2_FEATURE_RO_COMPAT_SUPP    (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
+                                        EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
+                                        EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
+#define EXT2_FEATURE_INCOMPAT_SUPP     (EXT2_FEATURE_INCOMPAT_FILETYPE| \
+                                        EXT2_FEATURE_INCOMPAT_META_BG)
+#define EXT2_FEATURE_INCOMPAT_UNSUPPORTED      ~EXT2_FEATURE_INCOMPAT_SUPP
+#define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED     ~EXT2_FEATURE_RO_COMPAT_SUPP
+
+#define EXT3_FEATURE_RO_COMPAT_SUPP    (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
+                                        EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
+                                        EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
+#define EXT3_FEATURE_INCOMPAT_SUPP     (EXT2_FEATURE_INCOMPAT_FILETYPE| \
+                                        EXT3_FEATURE_INCOMPAT_RECOVER| \
+                                        EXT2_FEATURE_INCOMPAT_META_BG)
+#define EXT3_FEATURE_INCOMPAT_UNSUPPORTED      ~EXT3_FEATURE_INCOMPAT_SUPP
+#define EXT3_FEATURE_RO_COMPAT_UNSUPPORTED     ~EXT3_FEATURE_RO_COMPAT_SUPP
+
 
 struct xfs_super_block {
        unsigned char   xs_magic[4];